Culture

Best grown in rich, fertile, medium moisture, well-drained soil in full sun to part shade. Add compost as needed before planting. Each plant will flower for approximately 7-10 days. Plant other species and cultivars with staggered bloom times to extend the total peony bloom period to approximately 6 weeks during May and June (in the St. Louis area). Remove spent flowers after blooming. Cut foliage to the ground and remove from the garden in fall after frost. Plants are long-lived, do not need to be divided and can be left undisturbed for years.

Noteworthy Characteristics

Paeonia tenuifolia, commonly called fernleaf peony, is a shrubby, herbaceous (soft-stemmed) plant that, each year, will typically grow to 1-2' tall by mid-spring, display attractive foliage throughout the summer and early fall, and then die to the ground after frost. This species features crimson flowers (to 3" across) which bloom in mid-season (usually May in the St. Louis area). Attractive green foliage is deeply divided and lobed into needle-like, ferny segments.

Genus name comes from the Greek name for Paeon, physician of the gods and reputed discoverer of the medicinal properties of plants in this genus.

Problems

Peonies are considered to be relatively pest free. Botrytis blight and Phytophthora blight are sometimes problems. Ants on peony buds are common and totally harmless. If plants do not flower, possible causes include but are not limited to: (1) planted too deep or too shallow, (2) too much shade, (3) late frost killed buds or (4) plant is too young or has been recently moved or disturbed.

Garden Uses

Fern leaf peony is attractive when planted in groups or as a specimen. Best in perennial borders. Also effective as an accent or small herbaceous hedge along fences, sidewalks, driveways or walls. Small size also makes this an interesting edging plant. Flowers are extremely showy, and the fern-like foliage usually remains attractive throughout the growing season.